The U.S. ambassador to Mexico has resigned after the publication of U.S. diplomatic cables that criticized that government’s anti-drug fight, infuriating the Mexican president.

Carlos Pascual appears to be the first senior U.S. diplomat to lose his job because of the WikiLeaks revelations. He had been stationed in Mexico for 19 months.

Secretary of State Hillary Rodham Clinton said in a statement Saturday evening that she had accepted Pascual’s resignation “with great regret.”

“Carlos has relayed his decision to return to Washington based upon his personal desire to ensure the strong relationship between our two countries and to avert issues raised by President [Felipe] Calderon that could distract from the important business of advancing our bilateral interests,” she said.

Calderon has publicly criticized Pascual, telling The Washington Post early this month that he was angered by the U.S. ambassador’s characterization of the Mexican army as “risk-averse” in going after drug traffickers. Calderon also said the cables laid bare U.S. attempts to play Mexican agencies off against one another in the drug fight. Calderon said he intended to talk to President Obama in a meeting on March 3 about his troubles with Pascual.

The White House and Clinton have steadfastly expressed support for Pascual, a 23-year veteran of the State Department and U.S. Agency for International Development.

Pascual has been a leading architect of U.S. policy toward Mexico, particularly the latest developments in the Merida Initiative, a joint effort to fight soaring drug violence. He is highly regarded at the senior levels of the State Department, and Clinton’s statement said he will assume a new position there.

Analysts say the opinions expressed by Pascual and other U.S. diplomats in the classified documents aren’t surprising to most people who follow the drug fight in Mexico. But the Mexican government clearly felt exposed upon publication of the criticism by a close ally, which became a media sensation.